Wuwa update - #2

- Stop tracking combos.json (personal data; combos.example.json seeds it)
- Ignore .pytest_cache/
- Merge PyInstaller into requirements.txt; drop requirements-build.txt
- Remove the built redesign mockup from docs/redesign/
- Web UI: remove the old key-image editor and multi-game leftovers,
  an unused team-image helper, and ~70 unused style.css rules
- Python: remove ComboTrackerEngine's 25 one-line pass-through methods;
  callers now use combo_engine_ui, combo_analytics, format_utils,
  stats_recording, step_introspection and parser directly
- Remove unused helpers: _step_accepts_input, combo_avg_ms, and
  input_normalization.split_inputs

- Characters: replace live encore.moe kits (text, multipliers, skill
  levels) with static/data/ww_characters.json: Basic chain hits (A1..),
  what holding LMB does, where LMB re-enters the chain after Intro/E/R/
  Heavy/Dodge/Mid-air, and move names with keys. Wolf's 14 characters
  are checked by hand; the rest are auto-drafted and labeled as such.
- tools/ww_build_moves.py drafts that file from a raw snapshot and
  keeps hand-checked entries. "Download raw data" (POST
  /api/ww/scrape-raw) saves encore.moe's unedited JSON to
  data/encore_raw/ (git-ignored) without changing what's shown.
- Timeline move names read the same data: chain entry points (e.g. LMB
  after Zani's E is Basic 3), and fuzzy matching for hand-typed names.
  Lucilla and Xuanling's hold LMB now continues the chain.
- Team rotations: remove DPS, calc links, damage sorting and the
  sheet's strategy commentary; the parser no longer keeps damage columns.
- Remove the header combo picker (duplicate of the combo list); the
  Teams page uses one team dropdown with portraits instead of cards.
- README: describe the inputs-only Characters page; fix port to 8737.